Patent GB-1484700-A (GB)
Title: Static converter incorporating thyristors
IPC: H01L23/473
Filed: 1974-10-11
Abstract: 1484700 Thyristor devices SIEMENS AG 11 Oct 1974 [31 Oct 1973] 44226/74 Heading H1K [Also in Division H2] A static thyristor converter, e.g. for high voltage inversion, rectification or static frequency changing, comprises (Figs. 1a 1b 1c) air or oil cooled columns 4 of thyristors stacked in tiers 1, 2, 3 on supporting rails 5, and supplied with coolant over ducts 6a, 6b, 6c from a common line; the coolant exhausting to a further common line over ducts 7a, 7b, 7c. Framework members 8 comprise flat sided hollow potshaped first support members 9 of, e.g. brass, and underlying second insulant support members 10, of e.g. cast resin one first support member 9 carrying the supporting rails 5 of each tier 1, 2, 3, which are mutually isolated by second support members 10. A further tier 11 carries a fuse assembly 12 on rail 5; first support members 9 carrying current to the fuse posts and the thyristors. Framework members 8, 8a are positioned respectively on the high and low voltage sides; first support members 9 of the low voltage side being screwed to conductive bolts 15a connected over lines 16 to thyristor column 4 of the same tier or over bus-bar 17 to bolt 16a of the subsequent tier, while each bolt 15a carries annular ferrite core 15b to constitute a suppression choke in circuit with the thyristor column. Bus-bars 17 are screwed through insulant spacers to first support members 9 of framework member 8 and current feed is taken over rail 19 and choke 15 of the tier 1. The complete framework is rectangular with carriers defined by framework members 8, 8a, while first support members 9 of each tier are conjoined by insulant rails supporting for each tier a central and circuit subassembly 22 for each thyristor of the stack. These comprise each an impulse amplifier and transmitter for firing the associated thyristors, with the resistors and capacitors of the circuit thereof. Busbars 17 conductively interconnect the tiers 1, 2, 3 between the suppression chokes 15 of the tiers and between fuse tier 11 and the ultimate suppression choke of the preceding tier 3. A choke 15 on framework member 8a is connected over line 16 to thyristor stack 4, and both chokes 15 of each first support member 9 are series connected over the support member so that thyristor stack 4 is preceded and followed by two chokes 15 per tier 1, 2, 3. The electrical circuit (Fig. 2, not shown) shows the chokes interconnected by the first support members to precede and follow the thyristor column of each tier, and connected over bus-bars to the chokes of the preceding and following tiers. Resistors and capacitors in series across each thyristor are accommodated in the respective control and circuit subassemblies. The several tiers are mutually insulated by the second support members 10 which also insulate the assembly from earth, and the input voltages (to which the number of tiers incorporated is proportioned) is applied to lines 13, 20. The first support members 9 are of cup shape and rectangular cross-section with inwardly sloping side walls (Figs. 3a, 3b, not shown) or may alternatively be of other shapes, e.g. hexagonal.